The 1960s ushered in a new era in US demographic history characterized by
significantly lower fertility rates and smaller family sizes. What catalyzed these
changes remains a matter of considerable debate. This paper exploits idiosyncratic
variation in the language of "Comstock" statutes, enacted in the late
1800s, to quantify the role of the birth control pill in this transition. Almost 50
years after the contraceptive pill appeared on the US market, this analysis provides
new evidence that it accelerated the post-1960 decline in marital fertility.
(JEL J12, J13, K10, N31, N32)